With the known ventilation systems, the air emerges through outflow vents having air guide elements such as vanes or rotating cages that are usually adjustable and near the outlet surface. The appearance of the outlet surface is characterized by the position of the guide elements and is not uniform. A covering of the guide elements on the outlet surface with a grid or the like is not possible since the orienting effect would be lost with such a covering.
Air vents are also known that have a diffusing effect. With these, the outlet surface can have a uniform appearance, but no orienting effect is possible, so that outflow devices with a diffusing effect are installed in the vehicle in addition to those with an orienting effect when both modes of air distribution are to be provided.
DE 197 21 831 A1 describes an air outflow device for the interior of a vehicle, comprising an air outlet element that can be rotated around an axis and that is provided with passages. Depending on the position of the air outlet element, the air is fed into the passenger compartment in a diffused or in a directed manner. The outlet surface changes its appearance, depending on the position of this air outlet element.
DE 100 11 932 C1 discloses a device for feeding air into a passenger compartment, the device being provided with two air outflow openings. Here, one air outflow opening serves for direct ventilation and the second for a diffuse air feeding.